Refrigerating apparatus



1963 J. J- PREOTLE ETAL 3,115,020

REFRIGERATING "APEARATUS Filed June 26, 1961 2 shee'hs sheet 1 I L n: {6

IN VEN TORS I John J Preozle Charles [I {-11 o) 6* V at THEIR ATTORNEYUnited States Patent 3,115,020 REFRIGERATING APPARATUS John J. Preotleand Charles E. Rembold, Dayton, Gino, assignors to General MotorsCorporation, Detroit, Mich., a corporation of Delaware Filed June 26,196i, Ser. No. 119,518 4 Claims. (til. 62-275) This invention pertainsto refrigerating apparatus and more particularly to foam insulatedrefrigerators and freezers.

High quality foam insulation has such improved insulation value that thewall thickness of refrigerators can be greately reduced and the size ofthe interior increased to provide a much larger storage space withoutincreasing the size of the exterior shell. Since such high quality foaminsulation is ordinarily not fireproof, especial precautions must betaken if electric wiring is embedded in the foam insulation.Furthermore, if wiring were embedded in the foam insulation, the wiringcould not be readily removed for inspection or repair without seriouslydiminishing the insulation properties of the refrigerator. Also, if therefrigerant conduits were passed through the foam insulation, they couldnot be readily removed when desired to remove the entire refrigeratingsystem from the cabinet. This would either prevent the use of apermanently sealed refrigerating system or it would substantiallyprevent the removal of such a refrigeration system from the cabinet.

It is an object of this invention to provide a foam insulatedrefrigerator arranged .in such a way that the wiring is kept a safedistance away from the foam insulation and is readily removable andaccessible.

It is another object of this invention to provide a foam insulatedrefrigerator arranged in such a way that the wiring is surrounded bynoninflammable materials some of which are sufficiently resilient topermit ready inspection, removal and replacement.

It is another object of this invention to provide a foam insulatedrefrigerator arranged in such a way that the refrigerant conduits arenot embedded in the foam insulation but are depressed into a resilientinsulation material from which they are readily removable.

These and other objects are attained in the form shown in the drawingsin which the space between the inner and outer shells irrnnediatelyaround the door opening is filled with an especially resilient fireproofelectrically non-conductive Fiberglas type of insulation in the form ofstrips. The wiring including low wattage heater wire surrounding thisportion of the cabinet is removably fastened to the inner surface of theouter shell by means of adhesive tape and is located adjacent to thisresilient insulation for the purpose of preventing condensation on theouter shell adjacent the door. The refrigerating system is arranged sothat the conduits extending from the liquefying means in the machinerycompartment extend through the strips of Fiberglas insulation to theavaporan ing means within the inner shell. Preferably, these conduitsare depressed into the surface of the resilient Fiberglas material. Theremainder of the space between the inner liner and outer shell is filledwith a high quality foam insulation allowing relatively thin walls to beused which will have a high insulating value.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

FIGURE 1 is a front view of a frozen storage refrigerator embodying oneform of my invention;

FIGURE 2 is a fragmentary enlarged vertical sectional 3,115,020 PatentedDec. 24., 1963 View taken substantially along the line 22 of FIG- URE 1;

FIGURE 3 is a fragmentary horizontal sectional View taken along the line3--3 of FIGURE 1; and

FIGURE 4 is a fragmentary horizontal sectional view taken along the line44- of FIGURE 1.

Referring now to the drawings, there is shown a refrigerator cabinet 20'including an outer shell 22 provided with a removable back wall 24fastened in place by screws 26. The front wall 28 of the outer shell hasan inwardlyturned U-shaped reinforcing flange 30 extending completelyaround the opening '32 for the insulated front door 34. To preventsweating of the outer shell 22 around the door opening 32, there areprovided low wattage heater wires 36 which are removably fastened atintervals tothe inner surface of the outer shell all around the dooropening by adhesive tape. Held in position over the heater wires 36 bythe U-shaped in-turned flanges 3% are strips 38 of an especiallyresilient fireproof, electrically non-conductive type of Fiberglas,known as the A-F type. This Fiberglas insulation 38 holds the wiring inplace in the event that the adhesive tape should come loose or bedamaged by the heat from the heater wire 36.

The inner liner 40, preferably of metal, is supported by thesubstantially rigid high quality foam insulation 42 which substantiallyfills all the space behind the strips of Fiberglas insulation 38.Because of its structural strength, the foam insulation 4-2 eliminatesthe need for any supporting brackets for the inner liner 4%. Because ofits high insulating value, the walls may be made relatively thin. Thefoam insulation material 42 may be introduced between the outer shell 22and the inner liner .0 after the Fiberglas strips 33 have been placedand after the heater wires 36 are in place. At this time, the innerliner til will be supported in proper position by a suitable fixture andthe foam insulation applied through the open rear wall of the outershell 22. After the foam material has been introduced into theinsulation space, the rear wall 24 is then applied and fastened in placeby the screws 26.

The refrigerant liquefying apparatus is provided in a machinerycompartment 44 located beneath the insulated walls surrounding the innerliner 40. In the machinery compartment 44 is located the sealed motorcompressor unit as provided with a suction conduit '48 and alsoconneoting through a discharge conduit with the condenser 50. Accordingto my invention, the condenser 50 connects to a capillary restrictortube 52 which together with the suction conduit 48 extends through anotch 54 in the front wall immediately beneath the right side of thedoor opening 32. This notch is normally covered by the front door 34.After passing through the notch 54, the suction conduit 48 and thecapillary tube 52 depress a groove and extend within the groove ordepression so formed in the strip 38 of resilient Fiberglas insulationextending across the bottom of the door opening 32. The suction conduit48 and the capillary tube 5-2 then extend through a notch in thein-turned flange at the front of the inner liner iii to the evaporator'56 located beneath the false bottom wall 58 in the bottom of the innerliner 40. The refrigerant conduits, namely, the suction conduit 4-8 andthe capillary tube 52, as well as the strips of Fiberglas insulation 38,are covered by the plastic breaker strips of which are readily removableand preferably snap into place.

The false bottom wall 58 encloses an evaporator compartment 62 betweenit and the bottom wall of the inner liner to. The evaporator 56 islocated in this evaporator compartment 62. Air from the main storagespace 64, enclosed by the inner liner 40, enters the evaporatorcompartment 62 through a plastic grille having two rows of openings 65located beneath the front edge of the false bottom wall 58 as shown inFIGURE 2. Air is removed from the rear of the evaporator compartment 62by a fan (not shown) which discharges upwardly through a duct 68 to theupper portion of the compartment 64 so as to recirculate the airtherein. Through rapid circulation of the air, the air in thecompartment 64 is kept at a desired frozen storage temperature, such asbetween 5 and F. This temperature is maintained by providing inelectrical series circuit with the motor-compressor unit 46 athermostatic control switch 70 within the machinery compartment having acapillary tube 72 extending through the notch 54 and the adjacent strip38 of Fiberglas insulation material to the second return bend on theadjacent side of the evaporator 56. The up-turned lower front flange ofthe inner liner is provided with an aperture through which the capillarytube 72 extends. The end of the capillary tube is preferably clamped tothe return bend 74 by conventional means.

During the pouring of the foam, the strips 38 of resilient Fiberglasinsulation prevent the leakage of escape of the materials forming thefoam insulation. The strips 38 are very resilient and firesafe and, whenthe breaker strip molding 60 is removed, can be readily removed andreplaced at any time desired. The removal of the strips 38 exposes thewiring 36 for inspection and repair. The refrigerating system comprisingthe liquefying apparatus and the evaporator 56 can be readily removed asa unit since the refrigerant conduits intervening rest in the lowerFiberglas strip 38 and are not permanently fastened in any way to thecabinet. The refrigerator switch 70 and its capillary tube 72 canlikewise be readily removed from the cabinet.

While the embodiment of the present invention, as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. A refrigerator including spaced inner and outer sheet metal wallsenclosing a storage compartment and provided with a door opening foraccess to said compartment, the periphery of said door opening having atleast a portion provided with a resilient insulation material, arefrigerant evaporating means surrounded by said inner walls, arefrigerant liquefying means located outside said outer walls,refrigerant conduit means connecting said liquefying and evaporatingmeans having a portion depressed within said resilient insulationmaterial, a cover for said resilient insulation material, and asubstantially rigid foamed plastic insulation material supporting saidresilient material and extending between and bonded to and providing astructural connection between said inner and outer walls behind saidresilient material.

2. A refrigerator including spaced inner and outer sheet metal wallsenclosing a storage compartment and provided with a door opening foraccess to said compartment, the pheriphery of said door opening havingat least a portion provided with a resilient insulation material, arefrigerant evaporating means surrounded by said inner walls, arefrigerant liquefying means located outside said outer walls, anelectrical wiring system having a portion directly associated with saidresilient insulation material and a portion connected to said liquefyingmeans, said liquefying and evaporating means being operativelyconnected, a cover for said resilient insula tion material, and asubstantially rigid foamed plastic insulation material supporting saidresilient material and extending between and bonded to and providing astructural connection between said inner and outer walls behind saidresilient material.

3. A refrigerator including spaced inner and outer sheet metal wallsenclosing a storage compartment and provided with a door opening foraccess to said compartment, the periphery of said door opening having atleast a portion provided with a resilient insulation material, arefrigerant evaporating means surrounded by said inner walls, arefrigerant liquefying means located outside said outer walls, anelectrical wiring system having a portion directly associated with saidresilient insulation material and a portion connected to said liquefyingmeans, refrigerant conduit means connecting said liquefying andevaporating means having a portion depressed within said resilientinsulation material, a cover for said resilient insulation material, anda substantially rigid foamed plastic insulation material supporting saidresilient material and extending between and bonded to and providing astructural connection between said inner and outer walls behind saidresilient material.

4. A refrigerator including spaced inner and outer sheet metal Wallsenclosing a storage compartment and provided with a door opening foraccess to said compartment, said outer sheet metal walls includinginwardly turned flange portions at said door opening, the periphery ofsaid door opening having at least a portion provided with resilientinsulation material in strip form supported by said inwardly turnedflange portions, a refrigerant evaporating means surrounded by saidinner walls, a refrigerant liquefying means located outside said outerwalls, refrigerant conduit means connecting said liquefying andevaporating means having a portion depressed within said resilientinsulation material, a cover for said resilient insulation material, anda substantially rigid foamed plastic insulation material supporting saidresilient material and extending between and bonded to and providing astructural connection between said inner and outer Walls behind saidresilient material.

References Cited in the file of this patent UNITED STATES PATENTS2,653,139

3. A REFRIGERATOR INCLUDING SPACED INNER AND OUTER SHEET METAL WALLSENCLOSING A STORAGE COMPARTMENT AND PROVIDED WITH A DOOR OPENING FORACCESS TO SAID COMPARTMENT, THE PERIPHERY OF SAID DOOR OPENING HAVING ATLEAST A PORTION PROVIDED WITH A RESILIENT INSULATION MATERIAL, AREFRIGERANT EVAPORATING MEANS SURROUNDED BY SAID INNER WALLS, AREFRIGERANT LIQUEFYING MEANS LOCATED OUTSIDE SAID OUTER WALLS, ANELECTRICAL WIRING SYSTEM HAVING A PORTION DIRECTLY ASSOCIATED WITH SAIDRESILIENT INSULATION MATERIAL AND A PORTION CONNECTED TO SAID LIQUEFYINGMEANS, RE-